The Incursions in Kadar Valley were part of a personal mission during the Swarm War in which Cpl. Kait Diaz was in search of the hidden Mount Kadar Laboratory to discover answers relating to her connection with the Swarm and Locust Horde. She was aided by Sgt. Marcus Fenix and Lt. Delmont Walker. Cpl. Diaz originally investigated the ruins of the New Hope Research Facility as it was where the Locust ancestors were created. Files from New Hope revealed that the the research at New Hope that lead to the creation of the Locust Horde were relocated to a hidden facility in Mount Kadar. The facility in Mount Kadar had sent out a radio message, but its point of origin was scrambled. Lt. Walker then suggested that they triangulate the source using the communication towers in the Kadar Valley.